Alkaline detergents, particularly those intended for institutional and commercial use, in combination with the presence of hard water commonly result in heavy scale formation that is difficult to control. The level of hardness in water can have a deleterious effect in many systems. For example, calcium carbonate precipitation on the surface of ware can negatively impact the aesthetic appearance of the ware, giving an unclean look. In general, hard water refers to water having a level of calcium and magnesium ions in excess of about 100 ppm expressed in units of ppm calcium carbonate. Often, the molar ratio of calcium to magnesium in hard water is about 2:1 or about 3:1. Although most locations have hard water, water hardness tends to vary from one location to another.
The control of such water hardness presents additional difficulty in ware wash applications employing high alkalinity and/or use at elevated temperatures. Traditionally, chelating agents and/or threshold agents are employed with high alkaline detergent compositions because of their ability to solubilize metal salts and/or prevent water hardness from scaling and/or precipitating. Although very high alkalinity detergent compositions provide desirable cleaning efficacy, there is a need for reducing the concentration of caustic in alkaline detergent compositions. This is a result of need for such very high alkalinity detergent compositions to be transported, handled and/or contacted by workers, each of which present safety concerns. For example, caustic detergent compositions can cause burns to exposed skin, particularly in the concentrated form. As the alkalinity of the compositions increases, the possible risk to workers also increases. Therefore, great care must be taken to protect workers who handle concentrated highly alkaline or caustic detergents.
There is also a need for continued development of low temperature dish washing machines and detergent compositions suitable for use therein. Beneficially, reducing temperatures employed in dish washing or ware wash machines results in energy savings and other benefits for consumers.
Accordingly, it is an objective of the present invention to develop detergent compositions to address at least one of these problems and/or to offer detergent compositions with usage, environmental and/or safety benefits.
Accordingly, it is an objective of the claimed invention to develop detergent compositions having low alkaline formulations. The formulations according to the invention may contain alkaline metal hydroxide or alkaline metal silicate as long as the concentrate pH is below 11.5.
A further object of the invention is a low temperature detergent compositions being caustic-free or low caustic or low alkaline and reducing and/or eliminating scale build-up of treated surfaces and/or enhanced protein removal.
A further object of the invention is to develop methods of employing caustic-free detergent compositions under low temperature ware washing conditions that further eliminate scale build-up and/or enhance protein removal on treated surfaces.